Steaming of oils, &amp;c.



UNITED STATES PATENT OFFICE.-

THUB'IJOWENSTEIN, OF CHICAGO, ILLINOIS.

s'rmmmc or OILS, 8w.

No Drawing.

To all whom it may concern:

Be it known that I, ARTHUR LOWENSTEIN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in the Steaming of Oils, &c.', of which the following is a specification.

My invent-ion relates to certain new and useful improvements in the heat treatment of such products as fatty acids and their glycerids. More particularly I am concerned with the heating of such materials for the purpose of deodorizing (in the case of the oils) and distilling (in the case of the acids), by direct contact with steam, the invention consisting primarily in the use of superheated steam of very low pressure for these purposes. The objects of the invention are, in general, to produce a technically superior product, and to reduce the cost of the treatment.

In the deodorizati'on and distillation-of cottonseed oil and other oils, fats, waxes and fatty acids, it has been customary to place the product in a closed vertical cylindrical tank provided with a vapor outlet at the top, internal closed coils the initial heating of the oil, up to the desired temperature, and a perforate spider or other distributer in the bottom for the ad.- mission of dry and saturated steam directly into the tank during the treating period proper. The process of deodorization as thus carried out usually required from six to eight hours to produce the desired result and was exceedingly wasteful of steam. Although a great deal of oil is still processed in this manner, two major improvements have been widely introduced which effect a considerable saving of time and of steam. The first improvement consisted in operating the refining tank or still under a vacuumoffrom 20 to 26" of mercury. The second improvement consisted in substituting for the dry and saturated or'normal live steam, super? heated steam. Such superheated steam however, as heretofore used, has invariably been superheated at relatively high pressuresusually at the common boiler-premure of 150 lbs. per m the ordinary superheater installation made use of in power plant practice having been employed for the purpose. In the use ofthis high pressure superheated steam in deodorizing and distilling, there is necessarily 'a great expansion of the steam as it enters the liquid'body of material under Specification of Letters Patent.

Application filed August 28, 1918. Serial No. 117,288.

of steam-pipe for Patented July 30, 1918.

treatment, I do not find thatsuch expansion v energy or velocity energy, with a consequent drop in temperature of the steam, and without any counterbalancing benefit to the process from the needlessly high outflow velocity attained. Furthermore, the temperature eifective for the treatment of the product is probably as low as or even lower than the final expanded temperature of the steam, and the initial superheat temperature must therefore be so far above this expanded temperature as to balance the drop which occurs in expansion. It follows therefore that the initial temperature of the steam is substantially above its effective temperature, and if the latter temperature is high enough to secure the desired result of deodorization or distillation in the shortest practicable time, the initial temperature will be dangerously high and capable of injuring that portion of the product which may be exposed to it, as for instance the film of liquid adjacent the exit nozzle'or perforation.

I find that these conclusions are fully confirmed by thepractice of my process. Not

only is there a great savlng of heat in the use of low pressure superheated steam in place of relatively high pressure steam, but the product, that is the deodorized oil or distilled acid, is noticeably superior in color to the product produced by the known processes.

The greatest economy may be efi'ected by my process where it is possible to make use of exhaust steam, that is steam which has been expanded down to a low pressure in the performance of useful work. It is then only necessary to install suitable separators or traps for removing water, oil or other impur1ties, and such steam may be led into superheaters of proper design and capacity, and fed from the latter directly to the stills or deodorizing tanks, the traps and superheaters bein all the additional equipment required an the steam being a waste product. Where exhaust steam in suflicient quantity is not available it may be supplemented or replaced by live steam from the ordinary power boilers, this steam being first expanded and then superheated, or special lowpressure boilers may be installed and coupled directly with the superheater. In each case, even Where live steam is expanded without doing work, there is a considerable saving in heat, and the low-pressure superheated steam, regardless of its source, produces a more nearly neutral and perfect refined or distilled product than does the high-pressure steam. The exact pressure of the steam which should be used for obtaining the full benefits of my invention will of course vary within reasonable limits according to the mechanical conditions met with in any specific'installation. In my work to date I have made use of steam pressures of from two to six pounds per in In order that the essential principles of my invention may be fully understood I will give one example of a process in accordance with the invention. A charge of twenty thousand pounds of cottonseed oil is let into a tank of the usual form above described. By means of the closed steam coils immersed in the oil within the tank the temperature is brought up to approximately 250 F. Exhaust steam, properly purified, and of a pressure of about 2% lbs. per in is led through a superheater in which it reaches a temperature of about 500 F., thence into the distributing spider at the base of the tank. A vacuum of about 25" of 'mercury is preferably maintained on the top of the oil (although this is not essential to my process, which is equally serviceable when operating at atmosphere pressure).

In from one and one half to seven hours (depending upon the nature of the oil and upon the use of a vacuum or atmospheric pressure) the treatmentwill be finished and the product will be of the highest grade and clear, and the invention is not to be re garded as limited in any way either by the foregoing particular description of the theories which I entertain and to which I attribute the benefits of the process or by the specific example given, except in so far as such limitations are included within the terms of the accompanying claims, in which it is my intention to claim all novelty inherent in my invention as broadly as is permissible in view of the prior art.

What I claim as new and desire to secure by Letters Patent is 1. The steps in thefprocess of heat-treating oils, fats, waxes," fatty acids and like products at pressures not substantially exceeding atmospheric which consist in superheating steam while at a relatively low pressure to a temperature suflicient to maintain the steam in a superheated condition after its expansion, and subjecting such products to the direct heating efiect of such low-pressure superheated steam, whereby the expansion of the steam during the treatment is rel-' liquid state to the direct action of a current of such superheated steam.

- LOVVENSTEIN. 

